Conventionally, a chain guide device is provided on a rear swing arm for guiding a chain wrapped between a drive sprocket mounted to an engine and a rear sprocket mounted to a rear wheel. The chain guide device includes a guide plate member formed of metal and a chain guide member formed of resin, whereby the chain guide member is surrounded and held by the guide plate member.
FIG. 4 of published patent application Japanese Utility Model Laid-open No. 3-5588 discloses a sectional view of a chain guide device 18 (reference numerals cited herein are those shown in the above mentioned publication). This chain guide device 18 includes a stay 41 with a forked shape and a lower opening provided on a rear fork 9, a sectionally U-shaped chain guide plate 42 (hereinafter referred to as plate member 42) connected to the stay 41 forming a ringlike portion, and a chain guide member 43 surrounded and held by the ringlike portion.
The plate member 42 and the chain guide member 43 are fastened together to the stay 41 by using a bolt 45 and a nut 46.
However, since the stay 41 is a forked member with a lower opening, a collar 43d that prevents the deformation of the stay 41 while securing the nut 46 to the bolt 45 is required. This results in an increase in number of parts required and an increase in weight.
Further, fastening the chain guide member 43 and the plate member 42 to the stay 41 using the bolt 45 and the nut 46 requires three types of insertion holes and a total of five holes. They include an insertion hole (axial hole) of the collar 43d fitted with a collar insertion hole h of the chain guide member 43, two insertion holes of the plate member 42, and two insertion holes of the stay 41. Accordingly, in integrating the chain guide device 18 with the rear fork 9, these five insertion holes must be aligned, such that mounting the chain guide device 18 to the rear fork 9 is troublesome.